Ransack search include parameter

I'm using gem 'ransack' to search records.

The page I'm programming starts with ONLY a dropdown to select @department. After that, I want Ransack to search within @department.

I need to include an additional parameter department=2 with the Ransack search parameters. (It works if I insert that into the browser URL).

Browser URL after I type in department=2

http://localhost:5000/departments/costfuture?department=2&utf8=%E2%9C%93&q%5Bid_eq%5D=&q%5Bproject_year_eq%5D=&q%5Boriginal_year_eq%5D=&q%5Bclient_id_eq%5D=43&q%5Blocation_name_cont%5D=&q%5Bproject_name_cont%5D=&q%5Bcoststatus_id_in%5D%5B%5D=&q%5Bcoststatus_id_not_in%5D%5B%5D=&q%5Brebudget_true%5D=0&q%5Bnew_true%5D=0&q%5Bconstruction_true%5D=0&q%5Bmaintenance_true%5D=0&commit=Search

This is the controller:

  def costfuture

    @departments = current_user.contact.departments
    if params[:department]
      @department = Department.find(params[:department])
      @search = @department.costprojects.future.search(params[:q])
      @costprojects = @search.result.order(:department_priority)
    end

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @departments }
    end
  end

I tried this in the view:

<%= search_form_for @search, url: departments_costfuture_path(:department => @department.id) do |f| %>

But, the resulting URL is missing the department=2.

Solution

If you want to pass the department option through to Ransack, you can do this with a hidden field within your search_form_for:

<%= search_form_for @search, url: departments_costfuture_path do |f| %>
  <%= f.hidden_field :department_eq, value: @department.id %>
  <%# Other form code here %>
<% end %>

But if you want to search a particular department, then it's better to use Rails routes for that. You can generate URLs like /departments/2/costfuture by modifying config/routes.rb:

resources :departments do
  get 'costfutures', on: :member
end

Now you can use the resulting URL helper to generate links that will set params[:id], and you can use that to retrieve @department.